<div class="refentry" lang="en" xml:lang="en"><a id="glStencilMask"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glStencilMask — control the front and back writing of individual bits in the stencil planes</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><p><code class="funcdef">void <b class="fsfunc">glStencilMask</b>(</code>GLuint <var class="pdparam">mask</var><code>)</code>;</p></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>mask</code></em></span></dt><dd><p>
                    Specifies a bit mask to enable and disable writing of individual bits
                    in the stencil planes.
                    Initially, the mask is all 1's.
                </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glStencilMask</code> controls the writing of individual bits in the stencil planes.
            The least significant
            <math overflow="scroll"><mi mathvariant="italic">n</mi></math>
            bits of <em class="parameter"><code>mask</code></em>,
            where
            <math overflow="scroll"><mi mathvariant="italic">n</mi></math>
            is the number of bits in the stencil buffer,
            specify a mask.
            Where a 1 appears in the mask,
            it's possible to write to the corresponding bit in the stencil buffer.
            Where a 0 appears,
            the corresponding bit is write-protected.
            Initially, all bits are enabled for writing.
        </p><p>
            There can be two separate <em class="parameter"><code>mask</code></em> writemasks; one affects back-facing polygons, and the other
            affects front-facing polygons as well as other non-polygon primitives.
            <a href="glStencilMask"><span class="citerefentry"><span class="refentrytitle">glStencilMask</span></span></a> sets both front
            and back stencil writemasks to the same values. Use <a href="glStencilMaskSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilMaskSeparate</span></span></a>
            to set front and back stencil writemasks to different values.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
            <a href="glStencilMask"><span class="citerefentry"><span class="refentrytitle">glStencilMask</span></span></a> is the same as
            calling <a href="glStencilMaskSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilMaskSeparate</span></span></a>
            with <em class="parameter"><code>face</code></em> set to <code class="constant">GL_FRONT_AND_BACK</code>.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
            <a href="glGet"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument
            <code class="constant">GL_STENCIL_WRITEMASK</code>, <code class="constant">GL_STENCIL_BACK_WRITEMASK</code>,
            or <code class="constant">GL_STENCIL_BITS</code>
        </p></div>
        {$pipelinestall}{$examples}
        <div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
            <a href="glColorMask"><span class="citerefentry"><span class="refentrytitle">glColorMask</span></span></a>,
            <a href="glDepthMask"><span class="citerefentry"><span class="refentrytitle">glDepthMask</span></span></a>,
            <a href="glStencilFunc"><span class="citerefentry"><span class="refentrytitle">glStencilFunc</span></span></a>,
            <a href="glStencilFuncSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilFuncSeparate</span></span></a>,
            <a href="glStencilMaskSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilMaskSeparate</span></span></a>,
            <a href="glStencilOp"><span class="citerefentry"><span class="refentrytitle">glStencilOp</span></span></a>,
            <a href="glStencilOpSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilOpSeparate</span></span></a>
        </p></div><div class="refsect1" lang="en" xml:lang="en"><div id="Copyright"><h2>Copyright</h2><p>
            Copyright © 1991-2006
            Silicon Graphics, Inc. This document is licensed under the SGI
            Free Software B License. For details, see
            <a href="https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/" target="_top">https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/</a>.
        </p></div></div></div>
